Archive for the ‘bluetooth’ Category

Pocket-sized OV-Chipkaart reverse engineering

Tuesday, March 1st, 2011

For those interested in reverse engineering the OV-Chipkaart system (aka Dutch public transport card that’s currently being hacked to shreds because of gross incompetence of Trans Link Systems); here’s an setup that’ll work and fit in your pocket :)

Just a Pandora with a common RFID reader. With the proper knowledge you can whip up your own within a few hours ;)

Also fun would be to replace the reader with a custom Bluetooth capable setup (the Pandora already has Bluetooth). To help you on your way I’ll leave you with these URL’s: an ISO 14443 RFID module combined with a Bluetooth serial bridge. Put it in a lunchbox or something innocent looking and they’ll never suspect a thing.

Hardware merge

Monday, July 19th, 2010

For the first time all components sit together on a breadboard (well actually 2 because the decoder board is so wide). And yes, things still work – UART, SDHC reading and decoder tests. Code wise things are also looking good. There’s still lots to do, but seeing less than 8kB FLASH and 850 byte RAM is used so far (without the FLAC patch) my current concern is speed. Doing a directory listing takes much longer than expected. Slow is normal at this stage (no 512 byte sector reading, dumping via ‘slow’ UART), but still.

The next step will be attempting to play a couple of songs, starting with a low bitrate MP3 up to a 50MB FLAC file. In the meantime, enjoy these two shots;

Bluetooth testing

Sunday, June 20th, 2010

Did some quick bluetooth testing and it works :) Nothing special, just to see if these modules communicate with other devices such as my laptop.

The module itself is pretty small and does not fit onto a breadboard itself, so what you see on the photo are actually 3 parts; the bluetooth module soldered onto a Bluetooth Bee PCB, which in turn is soldered onto a Xbee adapter PCB (the red PCB underneat). This particular BT module comes from Seeedstudio. They offer 2 options – separate module and PCB or PCB with module already attached. The Xbee adapter PCB is made by Sparkfun.